over the hill
US /ˌoʊvər ðə ˈhɪl/
UK /ˌoʊvər ðə ˈhɪl/

1.
lewat masa jayanya, terlalu tua
past one's prime; too old to be useful or effective
:
•
Some people think that once you reach 40, you're over the hill.
Beberapa orang berpikir bahwa begitu Anda mencapai usia 40, Anda sudah lewat masa jayanya.
•
Despite being over the hill, the veteran athlete still competed in the marathon.
Meskipun sudah lewat masa jayanya, atlet veteran itu masih berkompetisi di maraton.